Duret Hemorrhage: Etiology, Pathophysiology, Clinical Features, Imaging, Treatment, and Prognosis

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Introduction

Duret hemorrhage represents one of the most devastating complications of raised intracranial pressure (ICP) and brain herniation. First described by Henri Duret, this hemorrhage typically occurs in the brainstem, particularly the pons and midbrain, as a result of downward transtentorial herniation. Although relatively rare, it carries a high morbidity and mortality rate, making early recognition and management critical.

In this column, we will explore the cause, etiology, pathophysiology, epidemiology, clinical presentation, imaging features, treatment, and prognosis of Duret hemorrhage, referencing the attached case study and figures.

Case Background

A 64-year-old man with a history of hypertension, alcohol use disorder, and prior right-sided subdural hematoma requiring surgical decompression was found unconscious at home after head trauma.

Non-contrast CT scans revealed an acute left subdural hematoma with midline shift and signs of transtentorial herniation ([Figure 1], [Figure 2]). Following emergent decompression, subsequent scans revealed the development of a Duret hemorrhage in the pons ([Figure 3], [Figure 4]).

Figures

[Figure 1] Non-contrast Head CT (A) Coronal, (B) Axial – demonstrating acute left subdural hematoma with midline shift.

[Figure 2] Non-contrast Head CT (A) Axial, (B) Coronal – further confirming mass effect and ventricular compression.

[Figure 3] Post-operative Non-contrast Head CT (A) Axial, (B) Coronal – reduced subdural hematoma but new pontine hemorrhage.

[Figure 4] Post-operative Non-contrast Head CT (A) Axial, (B) Coronal – clear evidence of Duret hemorrhage within the brainstem.

Etiology and Causes

Duret hemorrhage is most commonly caused by transtentorial herniation, where the medial temporal lobe (uncus) is forced downward through the tentorial notch. This exerts pressure on the brainstem and its vascular supply.

Common etiologies include:

  • Intracranial hemorrhage: acute subdural or epidural hematomas.

  • Brain tumors: space-occupying lesions compressing the brainstem.

  • Severe traumatic brain injury.

  • Diffuse cerebral edema (e.g., hypoxic injury, hyponatremia).

  • Post-thrombolytic complications (rare).

  • Intracranial hypotension (rarely).

Pathophysiology

The prevailing mechanism involves stretching and tearing of the penetrating pontine and midbrain arteries due to caudal displacement of the brainstem.

  1. Vascular distortion:

    • The relatively fixed basilar artery branches (paramedian perforators) are stretched.

    • This results in linear or flame-shaped hemorrhages in the midline of the pons and midbrain.

  2. Venous infarction theory:

    • Herniation may obstruct venous drainage, leading to hemorrhagic venous infarction.

  3. Reperfusion injury hypothesis:

    • Restoration of blood flow after ischemia may trigger hemorrhage.

Key point: Duret hemorrhage is not a primary hemorrhage but a secondary vascular injury following raised ICP and herniation.

Epidemiology

  • Represents 5–10% of all brainstem hemorrhages.

  • Most frequently associated with traumatic brain injury and acute subdural hematoma.

  • Common in older adults with hypertension and in those with a significant alcohol history due to brain atrophy and fragile vessels.

  • Mortality remains extremely high, although rare reports describe survival with good recovery if ICP is rapidly controlled.

Clinical Presentation

Patients with Duret hemorrhage often present with severe neurological impairment, usually in the setting of known herniation.

Typical findings include:

  • Altered consciousness, often coma (GCS < 8 in most cases).

  • Anisocoria (unequal pupils) due to oculomotor nerve compression.

  • Loss of brainstem reflexes (corneal, gag, pupillary light reflex).

  • Abnormal posturing (decerebrate rigidity).

  • Irregular or ataxic breathing, progressing to respiratory arrest.

These findings are often preceded by clinical signs of raised ICP: headache, vomiting, and progressive neurological decline.

Imaging Features

CT Characteristics:

  • Linear or flame-shaped hemorrhages in the midline of the pons or midbrain.

  • Often associated with:

    • Midline shift

    • Compressed ventricles

    • Herniation evidence (e.g., obliterated basal cisterns).

  • Frequently occur after surgical evacuation of a hematoma, when the brainstem is decompressed ([Figure 3], [Figure 4]).

MRI Features:

  • T2/FLAIR: hyperintense lesions in the brainstem.

  • GRE/SWI: confirm hemorrhagic nature of the lesion.

  • Diffusion imaging may reveal ischemia preceding hemorrhage.

Differential Diagnosis

  • Primary hypertensive brainstem hemorrhage (typically larger, more lateral, without herniation signs).

  • Traumatic diffuse axonal injury (microhemorrhages, more diffuse).

  • Vascular malformations (e.g., cavernous malformations).

Treatment

Duret hemorrhage itself is often irreversible; hence, treatment focuses on preventing its occurrence through aggressive ICP management.

Acute management strategies:

  • Airway, breathing, circulation (ABC) stabilization.

  • ICP reduction:

    • Head elevation

    • Hyperventilation (temporary)

    • Osmotic therapy (mannitol, hypertonic saline)

  • Surgical evacuation of a hematoma (as in this case).

  • Treatment of underlying cause (tumor resection, CSF drainage, correction of hyponatremia).

Supportive care:

  • Mechanical ventilation for a comatose.

  • Neurointensive monitoring for secondary insults (hypotension, hypoxia).

Prognosis

Unfortunately, prognosis remains poor in most cases, with high mortality. Survivors often sustain severe neurological deficits due to irreversible brainstem injury.

However, a small subset of patients may recover with good outcomes, particularly when:

  • The hemorrhage is small.

  • ICP is rapidly controlled.

  • Prompt neurosurgical intervention is performed.

Quiz

Quiz 1. Which of the following best explains the etiology of Duret hemorrhage?
A. Hypertension-related spontaneous bleed
B. Venous malformation rupture
C. Stretching and tearing of pontine perforating arteries during transtentorial herniation
D. Direct trauma to the pons

Quiz 2. On CT, which feature is most characteristic of Duret hemorrhage?
A. Cortical subarachnoid hemorrhage
B. Flame-shaped midline brainstem hemorrhage
C. Basal ganglia hematoma
D. Lobar intraparenchymal bleed

Quiz 3. Which clinical finding is most suggestive of brainstem involvement in Duret hemorrhage?
A. Aphasia
B. Hemiparesis
C. Loss of pupillary reflex and abnormal breathing pattern
D. Seizure

Quiz 4. Which of the following interventions best reduces the risk of Duret hemorrhage?
A. Anticoagulation
B. Prompt control of elevated intracranial pressure
C. Sedative administration
D. Avoiding hyperventilation

Answer & Explanation

1. Answer: C. Explanation: Duret hemorrhage is secondary to brain herniation, not a primary hypertensive or traumatic bleed.

2. Answer: B. Explanation: Duret hemorrhages are classically flame-shaped and located in the midline pons or midbrain.

3. Answer: C. Explanation: Brainstem dysfunction is reflected by loss of reflexes, coma, and disordered respiration.

4. Answer: B. Explanation: Prevention by ICP control is key, since Duret hemorrhage is a secondary complication of herniation.

Conclusion

Duret hemorrhage serves as a dramatic reminder of the catastrophic consequences of uncontrolled intracranial hypertension. Although its prognosis is generally poor, early recognition of herniation syndromes, aggressive ICP management, and timely surgical intervention can occasionally lead to survival with meaningful recovery.

For clinicians, radiologists, and neurosurgeons, understanding the pathophysiology and imaging hallmarks of Duret hemorrhage is crucial in both diagnosis and management.

References

[1] N. Beucler, P. J. Cungi, A. Dagain, “Duret brainstem hemorrhage (descending transtentorial herniation): A systematic review and meta-analysis,” World Neurosurg., vol. 173, pp. 251-262.e4, 2023.

[2] K. L. Chew, Y. Baber, L. Iles, C. O'Donnell, “Duret hemorrhage: demonstration of ruptured median pontine branches of the basilar artery on minimally invasive post-mortem CT angiography,” Forensic Sci Med Pathol., vol. 8, no. 4, pp. 436-440, 2012.

[3] B. Gogia, A. Bhardwaj, “Duret Hemorrhage,” in StatPearls, Treasure Island (FL): StatPearls Publishing, 2022.

[4] H. S. Nguyen, N. B. Doan, M. J. Gelsomino, S. Shabani, W. M. Mueller, “Good outcome in a patient with Duret hemorrhage from acute subdural hematoma,” Int Med Case Rep J., vol. 9, pp. 15-18, 2016.

[5] P. M. Parizel, S. Makkat, P. G. Jorens, et al., “Brainstem hemorrhage in downward transtentorial herniation (Duret hemorrhage),” Intensive Care Med., vol. 28, no. 1, pp. 85-88, 2002.

[6] Case Study 73, “64-year-old man with head trauma – Duret hemorrhage,” Internal report, 2023.

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